Firstly, during using air nailing gun, different nailing power is usually needed in accordance with the xylon of the wood or specification of the nailing gun to drive nails into board materials, such that depths of the driven nails can meet the desired requirements of the users.
The NP of ANG depends on gas pressure and gas filling volume of inner cylinder. The gas pressure is supplied by gas pump (GP) connecting with the nailing gun (NG). Although the NP can be adjusted by altering output pressure of the GP, the adjustment is too rough to be controlled. Moreover, rated pressure often exists between the pump and the gun, so the wide scope of the pressure adjustment is not allowed.
The gas inputting/filling volume of cylinder depends on the travel distance of the balanced valve. However, the existing balanced valve of the air nailing gun (ANG) is fixed, so that the travel distance can not be adjusted, which is a defect resulting that the nailing power (NP) can not be adjusted. Moreover, invariable nailing power will increase gas consumption, increase noise, and reduce live time of the nailing gun. In addition, in the case of small nailing power needed, the scope of application of the existing ANG is limited.
Therefore, if nailing depth is to be controlled as needed, the existing nailing gun will achieve it by means of hand feeling, changing the distance between muzzle and board plate, swing speed of the nailing gun when firing, so that the adjusting effect depends on proficiency level of the users. For general users, the above method is difficult to master. Moreover, since the hand feeling varies with each nailing, the nailing depths can not be uniform.
Secondly, the travel distance of the balanced valve of the nailing gun is set to an optimum value in theory so as to provide maximum output power. However, due to manufacturing errors, the travel distance of the balanced valves corresponds to the maximum output power of each nailing guns will be different. Therefore, in fact, the travel distance of most balanced valves of the nailing guns does not achieve the optimum values.
Finally, the fixed travel distance of the balanced valve is not good for adjusting nailing frequency. The travel distance of the balanced valve will accomplish a stroke at each nailing. The travel distance of the balanced valve is in negative relation to the nailing frequency. In certain cases, it is needed to provide suitable nailing frequency to satisfy the habit of the user. It is obvious that the fixed travel distance of the balanced valve is not good for adjusting nailing frequency and further impacts the using comfort.